The scientists interviewed 230 male volunteers between the ages of 18-29 and asked how often they faked an orgasm.

Researchers explained:

On average, participants reported feigning orgasm in approximately one-fourth of sexual encounters in their current sexual relationship, most commonly during vaginal sex. [Reasons given included] feigning orgasm to support a partner's emotional well-being [and] feigning orgasm because one was intoxicated, having undesired sex, or out of a desire to improve.

OMG.

They also added it happened mostly during vaginal sex, but also during oral, anal and manual stimulation.